North Korea has conducted its final ground test of a solid-fuel rocket engine for a long-range ballistic missile, observed by leader Kim Jong Un, marking a significant step toward developing an arsenal capable of threatening the U.S. mainland.

This test is part of North Korea's ongoing efforts to develop and perfect intercontinental ballistic missiles (ICBMs), including the potential deployment of the Hwasong-20 system and more compact ICBMs that can be launched from various platforms or submarines.

Kim Jong Un has called for advancements in missile technology, including multi-warhead systems to improve penetration, although experts note re-entry technology may still be under development.

During recent high-level diplomatic interactions, China did not mention denuclearization in its meeting with Kim Jong Un, raising concerns about China's stance on North Korea's nuclear ambitions.

Analysts interpret China's apparent acceptance of North Korea's nuclear status as a response to its growing ties with Russia, aiming to maintain influence over Pyongyang.

Chinese President Xi Jinping sent a congratulatory letter to Kim Jong Un on North Korea’s founding anniversary, emphasizing the importance of strategic communication between the two countries, alongside Kim’s trip to Beijing.

North Korea has established unprecedented military cooperation with Russia, including sending around 13,000 soldiers to support Russia's war in Ukraine in exchange for security guarantees, foreign currency, and military technology.

Kim’s intensified missile testing and diplomatic activities follow the collapse of nuclear talks with the U.S. in 2019, aiming to pressure Washington and establish North Korea as a nuclear power while strengthening alliances with Russia and China.

Kim has provided military support to Russia’s Ukraine war and recently met with Xi Jinping and Putin, efforts seen as ways to boost leverage ahead of potential renewed talks with the U.S.

Kim’s visit to China, including a military parade, appears to have reinvigorated North Korea’s nuclear ambitions and solidified its alliances with China and Russia.

The solid-fuel rocket engine tested has a reported maximum thrust of 1,971 kilonewtons, a high figure that underscores North Korea’s advancing missile capabilities.

Solid-fuel missiles are considered highly threatening because they are easier to transport and quicker to deploy compared to liquid-fuel missiles.

Images from the test show Kim observing the engine’s flame with binoculars, with a visible red flame indicating a successful test.

South Korea and the U.S. are closely monitoring North Korea’s missile developments, with potential further assessments following the recent test.

Analysts suggest North Korea may conduct another ICBM test before the end of 2025, especially ahead of a major ruling party congress in early 2026 where Kim is expected to outline new policies.

Kim Jong Un has increased diplomatic support from Moscow and Beijing, including a historic visit to China in September 2025 where he met Xi Jinping and agreed to strengthen ties.